The embodiments described herein pertain generally to a multimodal sensor and a manufacturing method thereof.
Recently, there have been reports on technologies relating to electronic skin tactile sensors and chemical sensors, which can be applied to various fields such as biomonitoring systems, robot skin and haptic displays.
In conventional technologies, most tactile sensors with high sensitivity have been manufactured by using metals or inorganic substances. However, the sensors manufactured by using materials such as metals and inorganic substances are restrictive with respect to application fields. Accordingly, in order to realize electronic products such as electronic skin and flexible displays, it may be desirable to manufacture a flexible sensor by using flexible materials.
For the biomonitoring, development of a flexible electrode may be desirable to realize a tactile sensor having a flexible characteristic like human skin. However, in order to develop a flexible electrode, additional complicated processes like combination with a flexible polymer material and a patterning process are often used. Further, a sensor manufactured by these processes has a limit in size.
Meanwhile, most conventional chemical sensors sensing gas molecules are resistance-type sensors, and have detected resistance variation occurring when a chemical substance is adsorbed on a sensing layer. For the resistance-type sensors, there are technological issues regarding facilitating adsorption of a chemical substance on a sensing layer for high sensitivity of a sensor. That is, a resistance-type chemical sensor has a problem in that sensing is possible only when a sensing layer and a chemical substance directly react with each other. Accordingly, in order to enable a chemical substance to be fully adsorbed onto a sensing layer, the material for the sensing layer can be important. As such, most chemical sensors having high sensitivity use additional processes such as functionalization and combination of a sensing layer in order to improve the adsorption.
Korean Patent Application Publication No. 10-2011-0042924 (Title of Invention: Piezoresistive-Type Touch Panel, Manufacturing Method thereof, Display Device Including the Same, Touch Pad and Pressure Sensor) describes the example set forth above. Specifically, the patent application provides a method for manufacturing a piezoresistive-type touch panel, including: producing a polymer film, in which a piezoresistive film pattern with a resistance value varying depending on a pressure is embedded; producing a spacer layer to attach the spacer layer onto one side of the polymer film; and attaching a bottom substrate onto one side of the spacer layer.
Korean Patent Publication No. 10-0821699 (Title of Invention: Carbon Nanotube Chemical Sensor and Manufacturing Method thereof) also describes the example. Specifically, the patent provides a chemical sensor, which includes: an insulating layer stacked on a glass, silicon or ceramic substrate; at least one pair of electrodes stacked on a top portion of the insulating layer to face with each other; and a sensor, in which a multiple number of carbon nanotubes are diffused, forming a network structure, in a portion where the pair of electrodes are spaced from each other, wherein the multiple carbon nanotubes, and the pair of electrodes and the carbon nanotube terminals of the sensor are electrically conductive.